Madeleine was snatched from the family's holiday apartment on Thursday.

She had been left with her brother and sister, two-year-old twins Sean and Amelie. Her parents regularly checked on them as they dined in a restaurant nearby.

Police said they have found evidence she was abducted but have not disclosed any details.

There was speculation in the Portuguese media that police suspect a Briton or Britons because of the apparently meticulous planning and lack of forensic evidence.

Experts have put together an artist's impression of a `suspect' but have not publicly revealed it.

It was also reported that police were investigating a claim that a man was seen dragging a young girl towards a marina in nearby Lagos. Police have taken records of all boats booked into the marina last week.

A small party of about 20 volunteers have been searching forests on the outskirts of the village of Espiche.

Dave Felton, from Manchester who lives in the village, said: "I think people are still hoping that we don't actually find her and that she is safe and sound somewhere. If we find her then maybe it is not the best thing."